Yes, the Nutrimill grain mill will grind barley. It will also grind many other things such as what, corn, rye, and oats, as well as buckwheat.
I don't see why not, if you mean barley grass as dry seeds. However, if you're intending to use it to grind sprouted barley grass, be aware that this is going to make an enormous mess inside the grinder, and the burrs will have to be removed and cleaned.
People grind grain into flour in a mill.
Grain Mill
The machine could grind up grain easily.
To be used to grind grain.
to grind grain
That could be answered in two ways. Wheat loaf could be the exception as it has been manufactured but the others are just plants. Looking at it another way, sugar cane is not a grain. We don't grind its seeds, but we extract sugar from its stems.
to pump water; to grind grain
Mortar and pestle
You take the wheat (which is a grain) and grind it up.
no
Wash the barley in a clean water, dry it then grind in the mixer, start using by adding to the milk or you can make chapatis with it.